Co-extrusion spc foam flooring and manufacturing method thereof

ABSTRACT

A foam flooring includes a stone-plastic base material structure, which sequentially comprises, from top to bottom, a first stable layer, a foaming layer and a second stable layer. The first stable layer and the second stable layer are both sheets with a PVC resin and filler powder as main components, with 25-40 parts by mass of the PVC resin and 55-75 parts by mass of the filler powder; and the density of the SPC foam flooring is 1.4-1.6 g/cm3. The foaming layer is arranged between the two stable layers, such that the overall density of the flooring is significantly reduced and reaches 1.4-1.6 g/m3; since the foaming layer is arranged inside, the surface strength of the overall flooring is not influenced.

TECHNICAL FIELD

The present invention relates to a foam flooring, in particular an SPCfoam flooring, and a manufacturing method thereof.

BACKGROUND ART

With the continuous development of the PVC flooring industry, plasticflooring has gradually become an alternative material to traditionalflooring materials, such as wooden flooring, ceramic tile and reinforcedflooring. Industrial experts predict that plastic flooring will beaccepted by Chinese people as a commonly used decorative material forhome decoration in the next few years. With the rapid development of thereal estate industry, the load-bearing performance of the flooringmaterials has become a new requirement for high-rise home decoration andcommercial decoration, and stricter requirements have been imposed onPVC flooring products.

BRIEF DESCRIPTION OF INVENTION Technical Problem

Traditional SPC flooring has a density in the range of 1900 to 2000kg/m³. The high density of the SPC flooring leads to increased weightper unit area during the decoration and increased transportation costs.

Solution for the Problem Technical Solution

The present invention provides a SPC foam flooring to solve theaforesaid problem. This type of flooring is around 20 to 30% lighterthan traditional SPC flooring. It also exhibits improved dimensionalstability.

The technical solution of the present invention used to solve theaforesaid problem is as follows:

A co-extrusion SPC foam flooring, comprising a stone-plastic basematerial structure, wherein the stone-plastic base material structuresequentially comprises, from top to bottom, a first stable layer, afoaming layer and a second stable layer; the first stable layer and thesecond stable layer are both sheets with a PVC resin and filler powderas main components; wherein the amount of the PVC resin is 100 parts byweight and the amount of the filler powder is 200 to 300 parts byweight; the density of the SPC foam flooring is in the range of 1.4 to1.6 g/cm³.

As a preferred embodiment of the aforesaid technical solution, the firststable layer has a thickness in the range of 1 to 5 mm; the foaminglayer has a thickness in the range of 2 to 10 mm; the second stablelayer has a thickness in the range of 1 to 5 mm.

As a preferred embodiment of the aforesaid technical solution, thefiller powder is calcium carbonate or comprises calcium carbonate as amain component and one material selected from the group consisting ofcalcium bicarbonate, glass fiber and carbon fiber or any mixturethereof.

As a preferred embodiment of the aforesaid technical solution, the firststable layer and the second stable layer further comprise an additive,and the additive is one additive selected from the group consisting of acalcium zinc stabilizer, an internal lubricant, polyethylene wax,chlorinated polyethylene, acrylate, a composite lubricant and a colorantor any combination thereof.

As a further preferred embodiment of the aforesaid technical solution,when the foaming layer is a chemical foaming layer, the first stablelayer and the second stable layer further comprise the followingcomponents in parts by weight: 100 parts of polyvinyl chloride resinpowder, 200 to 300 parts of calcium carbonate, 4 to 7 parts of a calciumzinc stabilizer, 0.8 to 1.3 parts of an internal lubricant, 0.8 to 1.5parts of polyethylene wax, 4 to 6 parts of chlorinated polyethylene, 2to 5 parts of acrylate, 1.0 to 1.5 parts of a composite lubricant, and0.4 to 0.6 parts of a colorant.

As another further preferred embodiment of the aforesaid technicalsolution, when the foaming layer is a physical foaming layer, the firststable layer and the second stable layer further comprise the followingcomponents in parts by weight: 100 parts of polyvinyl chloride resinpowder, 250 to 270 parts of calcium carbonate, 5 to 6 parts of a calciumzinc stabilizer, 1.0 to 1.2 parts of an internal lubricant, 1.3 to 1.5parts of polyethylene wax, 5 to 6 parts of chlorinated polyethylene, 2to 3 parts of acrylate, 1.1 to 1.3 parts of a composite lubricant, and0.4 to 0.5 parts of a colorant.

Lubricants are divided into two types, internal lubricant and externallubricant. The main function of the external lubricant is to improve thefriction between the polymer fusant and the hot metal surface of theprocessing device. It is poorly compatible with the polymer and easilymigrates outwards from the fusant, so it can form a thin lubricationlayer at the interface between the plastic fusant and the metal.Internal lubricants are highly compatible with polymers and are presentinside the polymers to reduce the cohesive force within the polymermolecules so as to improve the frictional heat generation andflowability of the plastic fusant. External lubricants readily migrateoutwards from the fusant making it easy for the plastic fusant torelease from the mold after molding, so external lubricants are usuallyreferred to as mold release agent. However, internal lubricants andexternal lubricants may change depending on the properties of thefusant. For example, polyethylene wax and stearic acid are commonlubricants; when being used in polyethylene resin, polyethylene wax ishighly compatible with polyethylene resin and is retained inside theresin as an internal lubricant; when being used in polyvinyl chlorideresin, stearic acid is highly compatible and is retained inside theresin as an internal lubricant, but polyethylene wax is poorlycompatible and migrates outside the resin as an external lubricant.

Composite lubricants generally refer to polyol esters. Such lubricantsinclude lubricants comprising polyol esters obtained by esterificaiton,alcoholysis and interesterification of fatty acids, such as caprylicacid, decanoic acid, lauric acid, palmitic acid, oleic acid, stearicacid, arachidic acid, adipic acid, and sebacic acid, or polymercomposite alcohol ester products formed by multiple esterifications andcompounding of such fatty acids. In such lubricants, the polyol in thepolyol ester products is partially esterified, so there are unreactedhydroxyl groups in the ester. The polar hydroxyl groups usually impartexcellent antistatic effect to the products. Therefore, such lubricantsalso serve as an anti-static agent in PVC processing. Pentaerythritolfatty acid ester is a mixture containing monoester, diester, triesterand tetraester, and exhibits an excellent internal lubrication effect inPVC processing. Due to the difference in the extent of reaction, thistype of product is changed from internal lubricant to external lubricantwith increasing number of hydroxyl groups.

As a preferred embodiment of the aforesaid technical solution, thefoaming layer is a chemical foaming layer comprising the followingcomponents in parts by weight: 100 parts of polyvinyl chloride resinpowder, 150 to 200 parts of calcium carbonate, 4 to 7 parts of a calciumzinc stabilizer, 0.6 to 1.2 parts of a foaming agent, 0.5 to 0.9 partsof polyethylene wax, 2 to 3 parts of chlorinated polyvinyl chloride, 2to 3 parts of acrylate, 0.3 to 0.8 parts of a lubricant, and 6 to 9parts of a foaming regulator.

As a further preferred embodiment of the aforesaid technical solution,the foaming agent comprises 0.4 to 0.6 parts of a colorant.

As another preferred embodiment of the aforesaid technical solution, thefoaming layer is a physical foaming layer comprising the followingcomponents in parts by weight: 100 parts of polyvinyl chloride resinpowder, 300 to 330 parts of calcium carbonate, 4 to 7 parts of a calciumzinc stabilizer, 1 to 1.5 parts of an internal lubricant, 1 to 1.5 partsof polyethylene wax, 4 to 8 parts of chlorinated polyethylene, 3 to 5parts of acrylate, and 0.7 to 1.2 parts of a composite lubricant.

As a further preferred embodiment of the aforesaid technical solution,the foaming agent comprises 0.4 to 0.6 parts of a colorant.

As a preferred embodiment of the aforesaid technical solution, the SPCfoam flooring further comprises a decorative and protective structuresequentially comprising, from top to bottom, a UV coating, awear-resistant layer and a decorative layer.

As a preferred embodiment of the aforesaid technical solution, the UVcoating has a thickness in the range of 30 to 150 μm; the wear-resistantlayer is a polymer layer with a thickness in the range of 0.1 to 1.0 mm.

As a preferred embodiment of the aforesaid technical solution, thewear-resistant layer comprises PVC resin or vinyl resin as a maincomponent, and is formed by the blow molding, extrusion or drawingprocess after the addition of suitable amounts of plasticizer, lubricantand stabilizer.

As a preferred embodiment of the aforesaid technical solution, thedecorative layer is a PVC film with surface pattern.

Another objective of the present invention is to provide a method forpreparing the SPC foam flooring.

The method comprises the following steps:

-   -   a. Feeding the raw materials for the first stable layer and the        second stable layer into the high-speed mixer, mixing and        heating the raw materials, cooling the mixture under low-speed        stirring, extruding the mixture from the extruder A;    -   b. Feeding the raw materials for the foaming layer into the        high-speed mixer, mixing and heating the raw materials, cooling        the raw materials under low-speed stirring, introducing the raw        materials into the extruder B; in case of chemical foaming,        performing even melt plastification and extruding the raw        materials from the extruder B; in case of physical foaming,        performing even melt plastification for the raw materials in the        extruder B, injecting 4-10 wt % liquefied high-pressure carbon        dioxide into the foaming agent injection device, maintaining a        high pressure in the mold cavity to keep carbon dioxide in a        liquid state so as to completely mix with the material,        releasing the pressure during the course of extrusion;    -   c. Allowing the extrudate of the extruder A to enter the mold        flow channel distributor and converge with the extrudate of the        extruder B at the die head, co-extruding the mixture through the        die orifice of the die head to form the stone-plastic base        material structure;    -   d. Passing the plate released from the mold through an area        between the background pattern roller and the first mirror        finish roller to form the background pattern by compression,        transferring the stone-plastic base material structure to an        area between the second mirror finish roller and the embossing        roller; allowing the servo feeding roller for the wear-resistant        layer and the servo feeding roller for the decorative layer to        transfer the wear-resistant layer and the decorative paper        respectively to an area between the second mirror finish roller        and the air release roller, performing pre-lamination;        laminating the wear-resistant layer and the decorative paper on        the base material layer through the action of the second mirror        finish roller and the embossing roller to form the        wear-resistant layer and the decorative layer, as well as a        surface pattern with concave and convex three-dimensional effect        on the front face.

BENEFICIAL EFFECTS OF THE INVENTION Beneficial Effects

In summary, the present invention delivers the following beneficialeffects:

In the present invention, the foaming layer is disposed between twostable layers to significantly reduce the overall density of theflooring to 1.4 to 1.6 g/m³. Since the foaming layer is arranged inside,the surface strength of the flooring is not influenced and thesound-absorbing performance of the flooring is enhanced, and tests provethat the dimensional stability of the present invention is significantlyimproved.

BRIEF DESCRIPTION OF DRAWINGS Description of Drawings

FIG. 1 shows a schematic diagram indicating the structure of the presentinvention;

FIG. 2 is a schematic diagram indicating the device of the presentinvention;

FIG. 3 is a schematic diagram indicating the device according to Example1 of the present invention; wherein, 1—UV coating, 2—wear-resistantlayer, 3—decorative layer, 4—first stable layer, 5—foaming layer,6—second stable layer, 10—background pattern roller, 20—first mirrorfinish roller; 30—second mirror finish roller, 40—embossing roller,200—the servo feeding roller for the wear-resistant layer, 300—the servofeeding roller for the decorative layer, 400—air release roller.

MOST PREFERRED EMBODIMENT FOR CARRYING OUT THE INVENTION Best Mode forCarrying Out the Invention

As shown in FIG. 1 , a co-extrusion SPC foam flooring comprises adecorative and protective structure and a stone-plastic base materialstructure.

The decorative and protective structure sequentially comprises, from topto bottom, a UV coating (1), a wear-resistant layer (2) and a decorativelayer (3); the stone-plastic base material structure sequentiallycomprises, from top to bottom, a first stable layer (4), a foaming layer(5), and a second stable layer (6). The density of the SPC foam flooringis 1.531 g/cm³.

In this Example, the thickness of the UV coating (1) is 100 μm.

The wear-resistant layer (2) comprises a PVC resin as a main componentand is obtained by the calendering process after the addition ofsuitable amounts of plasticizer, lubricant and stabilizer. Its thicknessis 0.3 mm.

The decorative layer (3) is a PVC film with surface pattern. Itsthickness is 0.07 mm.

The first stable layer (4) and the second stable layer (6) are bothsheets with a PVC resin and filler powder as main components; whereinthe amount of the PVC resin is 100 parts by weight, the filler powder iscalcium carbonate with an amount of 250 parts by weight, and additivescomprising the following components in parts by weight are added:

5 parts of a calcium zinc stabilizerpart of an internal lubricant1.4 parts of polyethylene wax5 parts of chlorinated polyethylene2 parts of acrylateparts of a composite lubricant0.5 parts of a colorant

The aforesaid auxiliary agents are conventional auxiliary agents in theart, so there is no need to go into details.

The foaming layer (5) is a chemical foaming layer comprising thefollowing components in parts by weight:

100 parts of PVC resin powder160 parts of calcium carbonate6 parts of a calcium zinc stabilizer0.8 parts of a foaming agent0.6 parts of polyethylene wax2 parts of chlorinated polyvinyl chloride2 parts of acrylate0.5 parts of a lubricant7 parts of a foaming regulator0.5 part of a colorant

The aforesaid auxiliary agents are conventional auxiliary agents in theart, so there is no need to go into details.

As shown in FIG. 2 , the method for preparing the SPC foam flooring ofthis Example is as follows:

-   -   a. The raw materials for the first stable layer (4) and the        second stable layer (6) are fed into the high-speed mixer, mixed        and heated, cooled in the low-speed mixer, and are extruded from        the extruder A;    -   b. The raw materials for the foaming layer (5) are fed into the        high-speed mixer, mixed and heated, cooled under low-speed        stirring, introduced into the extruder B, subjected to melt        plastification and are extruded from the extruder B;    -   c. The extrudate of the extruder A is allowed to enter the mold        flow channel distributor and converge with the extrudate of the        extruder B at the die head, and the mixture is co-extruded        through the die orifice of the die head to form the        stone-plastic base material structure;    -   d. The plate released from the mold is passed through an area        between the background pattern roller (10) and the first mirror        finish roller (20) to form the background pattern by        compression, the stone-plastic base material structure is        transferred to an area between the second mirror finish roller        (30) and the embossing roller (40); the wear-resistant layer and        the decorative paper are transferred by the servo feeding roller        for the wear-resistant layer (200) and the servo feeding roller        for the decorative layer (300) to an area between the second        mirror finish roller (30) and the air release roller (400), and        are subjected to pre-lamination; the wear-resistant layer and        the decorative paper are laminated on the base material layer        through the action of the second mirror finish roller (30) and        the embossing roller (40) to form the wear-resistant layer and        the decorative layer, as well as a surface pattern with concave        and convex three-dimensional effect on the front face.

The properties comparison between the most preferred embodiment andconventional stone-plastic flooring (without foaming) is shown in theTable below.

Test results Co-extrusion ABA ABA foam stone-plastic Test stone-plasticflooring (most Test item standard flooring preferred embodiment)Dimensional ISO 0.13% 0.08% change rate 23999 after heating Curlingafter ISO 0.77 mm 0.30 mm heating 23999 Density ISO 1.984 g/cm³ 1.531g/cm³ 23996

EXAMPLES OF THE INVENTION Embodiments of the Invention

As shown in FIG. 1 , a co-extrusion SPC foam flooring comprises adecorative and protective structure and a stone-plastic base materialstructure.

The decorative and protective structure sequentially comprises, from topto bottom, a UV coating (1), a wear-resistant layer (2) and a decorativelayer (3); the stone-plastic base material structure sequentiallycomprises, from top to bottom, a first stable layer (4), a foaming layer(5), and a second stable layer (6). The density of the SPC foam flooringis 1.465 g/cm³.

In this Example, the thickness of the UV coating (1) is 100 μm.

The wear-resistant layer (2) comprises a PVC resin as a main componentand is obtained by the calendering process after the addition ofsuitable amounts of plasticizer, lubricant and stabilizer. Its thicknessis 0.3 mm.

The decorative layer (3) is a PVC film with surface pattern. Itsthickness is 0.07 mm.

The first stable layer (4) and the second stable layer (6) are bothsheets with a PVC resin and filler powder as main components; whereinthe amount of the PVC resin is 100 parts by weight, the filler powder iscalcium carbonate with an amount of 250 parts by weight, and additivescomprising the following components in parts by weight are added:

5 parts of a calcium zinc stabilizerpart of an internal lubricant1.4 parts of polyethylene wax5 parts of chlorinated polyethylene2 parts of acrylateparts of a composite lubricant0.5 parts of a colorant

The aforesaid auxiliary agents are conventional auxiliary agents in theart, so there is no need to go into details.

The foaming layer (5) is a physical foaming layer comprising thefollowing components in parts by weight:

100 parts of polyvinyl chloride resin powder330 parts of calcium carbonate5.5 parts of a calcium zinc stabilizerpart of an internal lubricant1 parts of polyethylene wax5.5 parts of chlorinated polyethylene3 parts of acrylateparts of a composite lubricant

The aforesaid auxiliary agents are conventional auxiliary agents in theart, so there is no need to go into details.

As shown in FIG. 3 , the method for preparing the SPC foam flooring ofthis Example is as follows:

-   -   a. The raw materials for the first stable layer (4) and the        second stable layer (6) are fed into the high-speed mixer, mixed        and heated, cooled under low-speed stirring, and are extruded        from the extruder A;    -   b. The raw materials for the foaming layer (5) are fed into the        high-speed mixer, introduced into the extruder B, mixed and        heated, cooled under low-speed stirring, subjected to even melt        plastification in the extruder B; 6 wt % liquefied high-pressure        carbon dioxide is injected into the foaming agent injection        device, a high pressure is maintained in the mold cavity to keep        carbon dioxide in a liquid state so as to completely mix with        the material, and the pressure is released during the course of        extrusion;    -   c. The extrudate of the extruder A is allowed to enter the mold        flow channel distributor and converge with the extrudate of the        extruder B at the die head, and the mixture is co-extruded        through the die orifice of the die head to form the        stone-plastic base material structure;    -   d. The plate released from the mold is passed through an area        between the background pattern roller (10) and the first mirror        finish roller (20) to form the background pattern by        compression, the stone-plastic base material structure is        transferred to an area between the second mirror finish roller        (30) and the embossing roller (40); the wear-resistant layer and        the decorative paper are transferred by the servo feeding roller        for the wear-resistant layer (200) and the servo feeding roller        for the decorative layer (300) respectively to an area between        the second mirror finish roller (30) and the air release roller        (400), and are subjected to pre-lamination; the wear-resistant        layer and the decorative paper are laminated on the base        material layer through the action of the second mirror finish        roller (30) and the embossing roller (40) to form the        wear-resistant layer and the decorative layer, as well as a        surface pattern with concave and convex three-dimensional effect        on the front face.

1.-10. (canceled)
 11. A co-extrusion SPC foam flooring, comprising astone-plastic base material structure, wherein the stone-plastic basematerial structure sequentially comprises, from top to bottom, a firststable layer, a foaming layer and a second stable layer; the firststable layer and the second stable layer are both sheets with a PVCresin and filler powder as main components; wherein the amount of thePVC resin is 100 parts by weight and the amount of the filler powder is200 to 300 parts by weight; and wherein the density of the SPC foamflooring is in the range of 1.4 to 1.6 g/cm³.
 12. The co-extrusion SPCfoam flooring of claim 11, wherein the thickness of the first stablelayer is in the range of 1 to 5 mm; the thickness of the foaming layeris in the range of 2 to 10 mm; and the thickness of the second stablelayer is in the range of 1 to 5 mm.
 13. The co-extrusion SPC foamflooring of claim 11, wherein the filler powder is calcium carbonate orcomprises calcium carbonate as a main component and one materialselected from the group consisting of calcium bicarbonate, glass fiberand carbon fiber or any mixture thereof.
 14. The co-extrusion SPC foamflooring of claim 11, wherein the first stable layer and the secondstable layer further comprise an additive, and the additive is oneadditive selected from the group consisting of a calcium zincstabilizer, an internal lubricant, polyethylene wax, chlorinatedpolyethylene, acrylate, a composite lubricant and a colorant or anycombination thereof.
 15. The co-extrusion SPC foam flooring of claim 11,wherein the foaming layer is a chemical foaming layer comprising thefollowing components in parts by weight: 100 parts of polyvinyl chlorideresin powder, 150 to 200 parts of calcium carbonate, 4 to 7 parts of acalcium zinc stabilizer, 0.6 to 1.2 parts of a foaming agent, 0.5 to 0.9parts of polyethylene wax, 2 to 3 parts of chlorinated polyvinylchloride, 2 to 3 parts of acrylate, 0.3 to 0.8 parts of a lubricant, and6 to 9 parts of a foaming regulator.
 16. The co-extrusion SPC foamflooring of claim 15, wherein the foaming layer comprises 0.3 to 0.5parts of a colorant.
 17. The co-extrusion SPC foam flooring of claim 11,wherein the foaming layer is a physical foaming layer comprising thefollowing components in parts by weight: 100 parts of polyvinyl chlorideresin powder, 300 to 330 parts of calcium carbonate, 4 to 7 parts of acalcium zinc stabilizer, 1 to 1.5 parts of an internal lubricant, 1 to1.5 parts of polyethylene wax, 4 to 8 parts of chlorinated polyethylene,3 to 5 parts of acrylate, and 0.7 to 1.2 parts of a composite lubricant.18. The co-extrusion SPC foam flooring of claim 17, wherein the foaminglayer comprises 0.4 to 0.6 parts of a colorant.
 19. The co-extrusion SPCfoam flooring of claim 11, wherein the SPC foam flooring furthercomprises a decorative and protective structure sequentially comprising,from top to bottom, a UV coating, a wear-resistant layer and adecorative layer.
 20. A method for preparing the co-extrusion SPC foamflooring of claim 19, comprising the following steps: a. Feeding the rawmaterials for the first stable layer and the second stable layer intothe high-speed mixer, mixing and heating the raw materials, cooling themixture in the low-speed mixer, extruding the mixture from the extruderA; b. Feeding the raw materials for the foaming layer into thehigh-speed mixer, mixing and heating the raw materials, cooling the rawmaterials in the low-speed mixer, introducing the raw materials into theextruder B; in case of chemical foaming, performing even meltplastification and extruding the raw materials from the extruder B; incase of physical foaming, performing even melt plastification for theraw materials in the extruder B, injecting 4-10 wt % liquefiedhigh-pressure carbon dioxide into the foaming agent injection device,maintaining a high pressure in the mold cavity to keep carbon dioxide ina liquid state so as to completely mix with the material, releasing thepressure during the course of extrusion; c. Allowing the extrudate ofthe extruder A to enter the mold flow channel distributor and convergewith the extrudate of the extruder B at the die head, co-extruding themixture through the die orifice of the die head to form thestone-plastic base material structure; d. Passing the plate releasedfrom the mold through an area between the background pattern roller andthe first mirror finish roller to form the background pattern bycompression, transferring the stone-plastic base material structure toan area between the second mirror finish roller and the embossingroller; allowing the servo feeding roller for the wear-resistant layerand the servo feeding roller for the decorative layer to transfer thewear-resistant layer and the decorative paper respectively to an areabetween the second mirror finish roller and the air release roller,performing pre-lamination; laminating the wear-resistant layer and thedecorative paper on the base material layer through the action of thesecond mirror finish roller and the embossing roller to form thewear-resistant layer and the decorative layer, as well as a surfacepattern with concave and convex three-dimensional effect on the frontface.